Reciprocating rotary tool carrier



July 7, 1970 C. G. MATSON RECIPROCATING ROTARY TOOL CARRIER Filed Feb. 12, 1968 INVENTOR. as. MATS ON United States Patent 3,518,902 RECIPROCATING ROTARY TOOL CARRIER Carl G. Matson, 401 E. Central Blvd Kewanee, Ill. 61443 Filed Feb. 12, 1968, Ser. No. 704,675 Int. Cl. B23b 39/00 US. Cl. 7733.5 4 Claims ABSTRACT OF THE DISCLOSURE A tool carrier adapted to be mounted on a table or like support and having a fluid power cylinder for reciprocating a hollow piston rod within which is journaled a shaft for driving a variety of tools such as drills, taps, etc. The shaft is driven by a motor and the reaction torque of the motor is taken by the table-mounted structure that includes the cylinder.

BACKGROUND OF THE INVENTION The prior art is replete with apparatus of the general character described above but is dominated by expensive and complicated devices and systems that seem to lack the design and engineering characteristics of compactness and few parts that perform plural functions. These devices accomplish generally the purpose of advancing and retracting a rotary tool such as a drill, tap, etc. under control of a system of limit switches and the like, but none of these provide a simple, self-contained structure designed for low-cost production, facile operation and ease of maintenance.

SUMMARY OF THE INVENTION The present invention features a simple structure comprising a fluid-pressurizable and pressure-exhausti-ble cylinder in which is mounted an annular centrally apertured piston fixed to a hollow piston rod that extends axially beyond the ends of the cylinder structure and in which is journaled a rotary shaft for carrying at one end thereof a variety of tools such as drills, taps, reamers, etc. The opposite end of the shaft is driven by a rotary driving means and the torque reaction of this means is taken by the structure through a plurality of guide means longitudinally slidably associated with the structure, in addition to which the driving means includes a motor driven by oil or other medium having lubricating qualities and leakage oil or other medium is used to lubricate the bearings by which the shaft is mounted in the hollow piston rod. As further features, the structure includes means external to the cylinder for implementing the guide means and for effecting mounting of the structure on a table or like support.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective of a preferred embodiment of the apparatus.

FIG. 2 is a plan of the same.

FIG. 3 is an enlarged section as seen generally along the line 3-3 of FIG. 1.

FIG. 4 is a section as seen along the line 4-4 of FIG. 3.

FIG. 5 is a section as seen along the line 55 of FIG. 3.

DESCRIPTION OF A PREFERRED EMBODIMENT Illustrated in broken lines in FIGS. 3 and 5 is a table or equivalent support on which is mounted a structure 12 that includes an elongated tubular member providing a hollow cylinder 14 having axially opposite ends to which are respectively aflixed end members 16 of plate-like nature having radially outwardly extending upper and lower portions 18 and 20, the expressions upper and lower being used here with respect to the illustrated embodiment,

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which happens to be mounted in such manner that the axis of the cylinder 14 is horizontal; but it will be understood that these and similar geographical expressions are used only in the interests of clarity, because the structure may be mounted vertically or in any other attitude.

The lower portions 20 include means, such as tapped bores 22 (FIG. 5), for mounting the structure on the table 10, as by means of cap screws 24. The upper portions serve as means for carrying a mount or plate 26 on which is mounted control means, here comprising a pair of limit switches 28 and 30, which may be of any wellknown types commonly employed as electrical controls in apparatus of this type. The plate 26 is secured to the mounting portions 18 by screws 32. Each end member 16 includes an inward extension 34 of circular section that fits tightly within the associated end of the tubular cylinder 14 and each extension has an annular-groove-received fluid seal 36 to seal an internal annular chamber 38 provided by the concentric relation of the cylinder 14 to an elongated tubular piston rod 40 that is axially slidably carried in coaxial apertures 41 in the end members 16, sealed at 43, and that has opposite end portions 42 and 44 projecting axially oppositely beyond the respective end members 16. An annulus 46 serving as a piston is axially fixed to the rod and is axially confined by snap rings 48 and provided with an internal annular seal 50 on the rod 44 and an outer annular seal 52 cooperative with the interior wall of the cylinder 14. The chamber 38 is selectively pressurizable and de-pressurizable at opposite sides of the piston 46 by means of a pair of passages 54 and 56 provided respectively in the end members 16. Conventional fluidtransmitting fittings 58 and 60 may be provided respectively in the passages 54 and 56 for connection to a suitable fluid pressure means (not shown), including a typical reservoir and valve means (also not shown, since they are well known).

From the description thus far, it will be seen that fluid pressure selectively introduced to the chamber 38 at opposite sides of the piston 46 will cause reciprocation of the piston and piston rod 40, so that a tool, such as a drill, tap, reamer, etc. (not shown), chucked beyond the piston rod end 42 (as will be described later) will move into and then out of a work piece (not shown), the limit switches, adjustably pre-settable by means such as a threaded rod 62 and stops 64, controlling the length of the advance and retract strokes of the reciprocating mechanism in cooperation with the limit switches.

Whichever tool is used with the rotary-reciprocating means is coaxially mounted in a chuck 66 that is a coaxial extension of a shaft 68 coaxially or concentrically disposed Within the tubular piston rod 40, a plurality of combination thrust and radial bearings 70 being used to journal the shaft in the piston rod so that the shaft is constrained for axial movement with the rod but can rotate relative to the rod, the latter being axially confined as respects a pair of outer elements 72 by means of snap rings 74, for example. These outer elements are in the form of plates fixed to a pair of guides or rods 76 as by means of cap screws 78, and the guides are spaced apart and parallel and external to the cylinder 14, being slidably engaged with or carried by the end members 16 (FIG. 4) by means of hearings or bushings 80. That is to say, because of the guide rods 76, the outer elements 72 are tied together and as such are constrained against relative angular movement about the axis of the cylinder 14. As such, this means provides a torque reaction for a driving means 82, here shown as a motor 84 mounted by a cup-shaped mount 86 which affords an internal chamber 88. This motor has an output shaft 90 having a coaxially keyed connection with a coupling 92 aflixed to the proximate end of the shaft 68 and is of the type that is driven by a medium such as oil or an equivalent medium having lubricating qualities, the selectively reversible inlet and outlet being shown at 94 and 96. Motors of this type of course experience inherent fluid leakage and for this purpose the chamber 88 is provided to collect oil to a level determined by a bleed hole 98. In the present instance, and with major axis of the structure horizontal, this bleed hole is above the axis of the cylinder 14 and therefore the chamber 88 can contain a sufficient quantity of oil to lubricate the bearings 70 before the excess drains away. The end members 16 are tied together, with the cylinder 14 between them, by a plurality of tie bars or rods 100, each secured at opposite ends respectively to the end members 16 by cap screws 102.

In the operation of the apparatus, the structure 12, being affixed to the table or the like, is stationary, and the piston rod 40 is reciprocable on advance and retract strokes, thus advancing and retracting whatever tool is chucked at 66 in the coaxial extension of the shaft 68 as driven by the motor 84, the torque reaction of which is taken by the structure 12 by means of the guide rods 76. The limit switches 28 and 30 may be selectively adjusted to control the timing and extent of the advance and retract strokes. The simplicity of the piston rod, containing the rotary shaft, whose torque reaction is taken by the basic structure 12, provides an economically sound design that employs only a few moving parts, tending toward easy maintenance of an apparatus that features low-cost production and an equally low selling price. Any of the well known valves etc. may be used for starting, stopping and varying the speed of the motor, and of the axial advance and retract of the tool, and for reversing the motor.

I claim:

1. A reciprocating rotary tool carrier comprising a support-mountable structure including a relatively short hollow cylinder having axially opposite terminal ends and plate-like end members respectively axially fitting said ends and respectively having coaxial circular openings therein, said end members respectively having extensions radially beyond the outer surface of the cylinder and a plurality of tie members externally of and parallel to the cylinder and extending between and connected to said extensions for securing the members together with the cylinder therebetween, said end member extensions respectively having bores therein axially alined on an axis paralleling the cylinder axis, an elongated tubular piston rod concentrically within the cylinder and axially slidably carried by the end member openings and having opposite outer end portions projecting axially oppositely beyond the respective end members, the annular interior space between the rod and structure providing a fluid pressure-receivable and pressure-exhaustible chamber, an annular piston fixed to the rod within the chamber and selectively pressurizable at opposite sides, means on the structure for affixation thereof to a support, a pair of passage means in the structure for selectively pressurizing opposite sides of the piston to cause reciprocation of the rod, a pair of outer radial elements fixed respectively to the outer end portions of the rod, elongated guide means external to the cylinder and secured to the elements and extending parallel to the cylinder axis and longitudinally slidably mounted'in the aforesaid bores of the end member extensions for preventing rotation of the elements relative to the structure about the cylinder axis, a tool driving shaft extending coaxially through and journaled in the piston rod and having opposite outer ends projecting respectively axially beyond the elements, and rotary driving means including a motor having a casing coaxially fixed to and carried by one element and a driving shaft coaxially connected to and for driving the tool driving shaft.

2. The invention defined in claim 1, in which each end member extension has a plurality of bores as aforesaid, said bores carry bushings and the elongated guide means includes a plurality of rods respectively extending through and axially slidably carried by the bushings.

3. The invention defined in claim 1, in which each end member has an integral circular projection extending axially into and tightly fitting the respective terminal end of the cylinder and each connection thus provided includes an annular seal.

4. The invention defined in claim 1, in which the motor shaft is connected to the tool driving shaft by an axially separable coupling contained within the proximate end portion of the piston rod.

References Cited UNITED STATES PATENTS 3,304,051 2/1967 Calhoun 253-3 2,930,261 3/1960 Emrick 77-335 2,832,858 4/1958 Tydeman 7733.5 XR 2,542,866 2/1951 Grossman 77-335 FRANCIS S. HUSAR, Primary Examiner U.S. C1. X.R. 

